JP2022158155A - Method for manufacturing rod lens array, and method for manufacturing member for lens fixation - Google Patents

Abstract

To provide a method for manufacturing a rod lens array which can suppress loosening when an exposed lens surface of a rod lens is polished in a state where base material surfaces of a lens block are bonded to each other and bundled.SOLUTION: A method for manufacturing a rod lens array includes: a first step of manufacturing a sheet-like base material containing a resin, and a member for lens fixation having an adhesive layer overlapping one surface of the base material; a second step of manufacturing a lens board sandwiching a plurality of rod-like rod lenses between each adhesive layer of two members for lens fixation; a second step of manufacturing a plurality of lens blocks by dividing the manufactured lens board; and a third step of polishing the rod lens that the manufactured lens block has, and obtaining a rod lens array.SELECTED DRAWING: None

Description

The present invention relates to a method of manufacturing a rod lens array having, for example, a structure in which a plurality of rod-shaped lenses are arranged between two substrates.
The present invention also relates to a method of manufacturing a lens fixing member for sandwiching and fixing the plurality of rod-shaped lenses, for example.

2. Description of the Related Art Conventionally, a rod lens array used as an optical component in copiers, printers, etc. is known. This type of rod lens array has, for example, a lens block shape obtained by cutting and dividing a lens board in which a large number of rod-like (rod-like) lenses are sandwiched between two substrates. The substrate is, for example, a resin-containing plate such as a glass fiber reinforced plastic plate, and the lens is, for example, a rod lens made of glass or plastic (for example, Patent Documents 1 and 2).

A manufacturing method for this type of rod lens array includes an assembly process in which a large number of fiber-like lens materials are aligned on one substrate and the other substrate is arranged and fixed thereon; A filling and curing step of filling the gaps of the array with a resin and curing the resin, a cutting step of cutting the lens blocks bonded and integrated by the cured resin into predetermined lens lengths, and a polishing step of polishing the cut end surfaces. is known (for example, Patent Document 3).

In the manufacturing method described in Patent Document 1, as the resin to be suction-filled into the gaps of the lens material array in the filling and curing step, a spherical organic filler having an average particle size of 0.1 to 25 μm subjected to monodispersion treatment is used as the filler. An addition reaction type silicone resin containing 0.1 to 20% by mass and having a viscosity of 500 to 1500 mPa·s is used.
According to the manufacturing method described in Patent Document 1, it is possible to stably manufacture a rod lens array having good arrangement and optical characteristics and high strength.

JP-A-09-090105 Japanese Patent No. 4319301 Japanese Patent Application Laid-Open No. 2006-309078

By the way, in the manufacturing method of the rod lens array, there is a case where the substrate is produced by press molding. In the production of such a base material, the material for the base material is sandwiched between resin separators and press-molded in this state. In addition, there is a case where a lens board having rod lenses is cut to a predetermined length to produce small lens blocks, and exposed lens surfaces are formed at the cut ends of the rod lenses of the lens blocks. Specifically, there is a case where a lens board formed by sandwiching a plurality of rod lenses between two base materials is cut in the thickness direction to produce a lens block, and exposed lens surfaces are formed on the rod lenses. In such cases, in order to polish the formed exposed lens surfaces, multiple lens blocks are bundled so that the exposed lens surfaces are flush with each other, and the base surfaces of the lens blocks are glued together with an adhesive in the bundled state. be. Then, each exposed lens surface of the plurality of lens blocks is polished in a bundled state.

However, since the resin separator used in the press molding process contains phenolic antioxidants such as dibutylhydroxytoluene (BHT), the phenolic antioxidant contained in the separator is Adheres to the surface of the base material by the molding process. Using a base material with a phenolic antioxidant attached to the surface, and bonding the base material surfaces of the lens block together with an adhesive as described above, the phenolic antioxidant exerts the original adhesive strength of the adhesive. As a result, the adhesive strength of the adhesive is weakened, and the bundled lens blocks tend to come loose during polishing.

In view of the above problems, the present invention provides a rod lens array that can suppress the looseness when the exposed lens surfaces of the rod lenses are polished in a state in which the base surfaces of the lens blocks are bonded and bundled. An object is to provide a manufacturing method.
Another object of the present invention is to provide a method of manufacturing a lens fixing member for producing a lens board by sandwiching a plurality of rod lenses from both sides and capable of suppressing the above looseness. do.

A method for manufacturing a rod lens array according to the present invention includes:
a first step of producing a lens fixing member having a sheet-like base material containing a resin and an adhesive layer superimposed on one surface of the base material;
a second step of producing a lens board in which a plurality of rod-shaped rod lenses are sandwiched between the respective adhesive layers of the two lens fixing members, and further dividing the produced lens board to produce a plurality of lens blocks;
a third step of obtaining a rod lens array by subjecting the rod lenses of the manufactured lens block to a polishing process;
In the second step, the lens board is produced by arranging the plurality of rod lenses in the same longitudinal direction, and the lens board is cut in the thickness direction in a direction perpendicular to the longitudinal direction of the plurality of rod lenses. dividing the lens board into a plurality of lens blocks by forming an exposed lens surface on the lens blocks;
In the third step, a plurality of the lens blocks are bundled so that the exposed lens surfaces of the rod lenses are aligned, and the exposed lens surfaces are bonded to each other by bonding the base surfaces of the adjacent lens blocks with an adhesive. obtain a rod lens array by subjecting the
The first step is
a cleaning step of cleaning the surface of the substrate in order to reduce the phenolic antioxidant adhering to the surface of the substrate to be bonded and improve the adhesive strength of the adhesive;
In the purification step, the surface of the base material to which the phenolic antioxidant is adhered and to be adhered by the adhesive is irradiated with light containing ultraviolet rays having a wavelength of 300 nm or less to prevent the phenolic antioxidant. reduce drugs.
According to the above-described manufacturing method, it is possible to suppress scattering when the exposed lens surfaces of the rod lenses are polished in a state in which the base surfaces of the lens blocks are bonded and bundled.

In the manufacturing method described above, the substrate may be an epoxy glass laminate.

In order to solve the above problems, a method for manufacturing a lens fixing member according to the present invention comprises:
The lens fixing member is manufactured in order to make a rod lens array having a plurality of rod lenses arranged so that their optical axes are aligned, and two lens fixing members that sandwich and fix the plurality of rod lenses. A method for manufacturing a lens fixing member comprising:
The lens fixing member has a sheet-like base material containing a resin and an adhesive layer superimposed on one surface of the base material,
In order to improve the adhesive strength when the surfaces of the base material are adhered to each other with an adhesive during the process of making the rod lens array, the amount of the phenolic antioxidant adhering to the surface of the base material is reduced. Equipped with a purification process to purify the surface,
In the purification step, the surface of the base material to which the phenolic antioxidant is adhered and to be adhered by the adhesive is irradiated with light containing ultraviolet rays having a wavelength of 300 nm or less to prevent the phenolic antioxidant. It is characterized by reducing the agent.
By adopting the above cleaning method, a lens block is produced using the base material whose surface has been cleaned as described above, and the base material surfaces of the lens block are bonded together and bundled together to form the exposed lens of the rod lens. When the surface is polished, it is possible to suppress the looseness of the bundled lens blocks.

According to the method for manufacturing a rod lens array according to the present invention, it is possible to suppress scattering when the exposed lens surfaces of the rod lenses are polished in a state in which the base surfaces of the lens blocks are bonded and bundled.
Further, according to the method of manufacturing a lens fixing member according to the present invention, it is possible to manufacture a lens fixing member capable of suppressing the above-described looseness.

FIG. 1 is a schematic diagram schematically showing an example of a rod lens array obtained by the manufacturing method of this embodiment. FIG. 2 is a cross-sectional view schematically showing how the substrate is produced. FIG. 3A is a schematic diagram schematically showing how the substrate surface is purified. FIG. 3B is a schematic diagram schematically showing a state in which an adhesive layer is laminated on a substrate. FIG. 4A is a schematic diagram schematically showing how a lens board is manufactured. FIG. 4B is a schematic diagram schematically showing how the lens board is manufactured. FIG. 5A is a schematic diagram schematically showing how a lens board is cut to produce a lens block. FIG. 5B is a schematic diagram schematically showing how a lens block is produced by cutting the lens board. FIG. 6A is a schematic diagram schematically showing how exposed lens surfaces in a plurality of bundled lens blocks are polished. FIG. 6B is a schematic diagram showing how a plurality of lens blocks that have once been bundled are separated. FIG. 7 is a graph showing TOF-SIMS analysis results.

An embodiment of a method for manufacturing a rod lens array according to the present invention will be described below with reference to the drawings.

A rod lens array 10 manufactured by the manufacturing method of the present embodiment has a plurality of rod lenses 12 having polished exposed lens surfaces, as shown in FIG. A plurality of rod lens arrays 10 are used in combination. For example, the rod lenses 12 are arranged so that the optical axis directions of the rod lenses 12 are aligned.

The method for manufacturing the rod lens array of the present embodiment (hereinafter also simply referred to as the manufacturing method) includes:
a first step of producing a lens fixing member 15 having a sheet-like base material 11 containing a resin and an adhesive layer 13 overlapping one surface of the base material 11;
A lens board 10″ having a plurality of rod-shaped rod lenses 12 sandwiched between adhesive layers 13 of two lens fixing members 15 is produced, and the lens board 10″ thus produced is divided into a plurality of lens blocks 10′. a second step of making;
and a third step of obtaining the rod lens array 10 by subjecting the rod lenses 12 of the manufactured lens block 10′ to a polishing process,
In the second step, a lens board 10 ″ in which a plurality of rod lenses 12 are aligned in the longitudinal direction is produced, and the lens board 10 ″ is arranged in the thickness direction in a direction perpendicular to the longitudinal direction of the plurality of rod lenses 12 , 12 . dividing the lens board 10″ by cutting to produce a plurality of lens blocks 10′, and forming exposed lens surfaces on the lens blocks 10′;
In the third step, a plurality of lens blocks 10' are bundled so that the exposed lens surfaces of the rod lenses 12, 12 are aligned, and the base surfaces of the adjacent lens blocks 10' are adhered to each other with an adhesive. A rod lens array 10 is obtained by polishing the surface,
The first step is
A cleaning step for cleaning the surface of the base material 11 to reduce the phenolic antioxidant adhering to the surface of the base material 11 to be bonded and improve the adhesive strength of the adhesive,
In the purification step, the phenolic antioxidant is reduced by irradiating light containing ultraviolet rays with a wavelength of 300 nm or less to the surface of the base material to which the phenolic antioxidant is attached and to be adhered by the adhesive. The surface of the substrate 11 is cleaned. Here, "improving the adhesive strength" means that the adhesive strength of the adhesive, which is inhibited by the phenolic antioxidant, is exhibited with the original adhesive strength of the adhesive, and that the substrate surface is purified to prevent phenolic oxidation. making the adhesion stronger when the inhibitor is reduced than before the reduction.

In the first step, a sheet-like base material 11 for sandwiching the rod lens 12 is prepared. The sheet-like base material 11 contains at least resin. The sheet-shaped base material 11 may contain 20% by mass or more and 40% by mass or less of resin. The thickness of the manufactured sheet-like base material 11 may be, for example, 0.1 mm or more and 3.0 mm or less.

The base material 11 used in the first step is, for example, formed into a sheet by subjecting a base material material to a press molding process. In the press molding process, a separator S is used to separate the sheet-shaped substrates 11 from each other.

A substrate material for producing the sheet-like substrate 11 includes, for example, a resin composition that can be deformed by press molding, and fibers embedded in the resin composition. The substrate 11, which is a fiber-reinforced plastic plate, is produced by subjecting such a substrate material to a press molding process. The base material 11 may be produced by subjecting a plurality of sheet-like base material materials in a laminated state to press molding. The fiber reinforced plastic plate may be an epoxy glass laminate.

When the substrate 11 is an epoxy glass laminate, the substrate material includes, for example, an uncured sheet-like epoxy resin composition and glass fiber cloth (glass cloth). Specifically, the base material may be a prepreg or the like obtained by impregnating a glass fiber cloth with a solution containing an epoxy resin and then drying the cloth. An epoxy glass laminate containing a cured epoxy resin and a glass fiber cloth is produced by heat-press molding a plurality of such substrate materials (prepregs) stacked in a press molding process. If necessary, a drying treatment may be further applied.

The separator S is, for example, a resin film. The material of the separator S is not particularly limited, and polyolefin such as polyethylene or polypropylene, for example, is adopted. As polypropylene, for example, biaxially oriented polypropylene may be employed.

The separator S contains a phenolic antioxidant. A phenolic antioxidant is an antioxidant having a phenolic structure in the molecule. Examples of phenolic antioxidants include dibutylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).

In the press molding process, the plurality of separators S are arranged so as to separate the plurality of sheet-like substrate materials from each other. For example, as shown in FIG. 2, a plurality of separators S are arranged between adjacent substrate materials (substrates 11) so as to separate adjacent substrate materials (substrates 11). The separator S adheres to the substrate material (substrate 11) under pressure by the press molding process, but has releasability so that it can be easily separated from the substrate material (substrate 11) after the press molding process.

In the press molding process, the pressure condition is, for example, 1 MPa or more and 30 MPa or less. The temperature conditions are, for example, 140° C. or higher and 210° C. or lower.

By the press molding process, the base material 11 is directly contacted with the separator S containing the phenolic antioxidant and is subjected to pressure. Therefore, the phenolic antioxidant adheres to the surface of the substrate 11, although the amount is relatively small.
The phenolic antioxidant adhering to the surface of the base material 11 can cause a weakening of adhesive strength when the base materials are to be adhered to each other with an adhesive.

The base material 11 may be further subjected to heat treatment under temperature conditions higher than those set in the press molding process. When the substrate 11 is a fiber-reinforced plastic plate such as an epoxy glass laminated plate, heat treatment (high-temperature curing) can further increase the adhesion between the fibers contained in the fiber-reinforced plastic plate and the plastic. .
In addition, as the base material 11, the commercial item produced by the press molding process as mentioned above can be used.

In the manufacturing method of the present embodiment, the first step is, for example, reducing the phenolic antioxidant adhering to the surface of the substrate 11 as described above, and reducing the adhesive on the surface of the substrate to be bonded in the subsequent bonding step. A cleaning step is provided to clean the surface of the substrate 11 in order to improve the adhesion. Further, the first step is a lens fixing member manufacturing step of manufacturing a lens fixing member 15 having a sheet-like base material 11 containing a resin and an adhesive layer 13 overlapping one surface of the base material 11. have

In the cleaning step of the first step, the surface of the base material 11 to be bonded with the adhesive later is irradiated with light containing ultraviolet rays having a wavelength of 300 nm or less. As a result, the amount of the phenolic antioxidant adhering to the surface of the substrate 11 due to the press molding process described above is reduced. Therefore, it is possible to improve the adhesive strength of the adhesive in the bonding step described in detail later, and to firmly bond the adjacent substrate surfaces.

Specifically, in the purification step, the phenolic antioxidant is decomposed by irradiating the surface of the substrate to which the phenolic antioxidant is attached with light containing ultraviolet rays having a wavelength of 300 nm or less. As a result, the surface of the base material to be adhered later is purified, so that the adhesive strength of the adhesive can be fully exhibited. Therefore, in the later detailed polishing step, the bundled lens blocks 10' can be prevented from coming apart.
On the other hand, if a relatively large amount of phenolic antioxidant is present on the base material surface, for example, the wettability of the adhesive to the base material surface may deteriorate, or the curing reaction of the curable adhesive due to the phenolic antioxidant may occur. is hindered. As a result, there is a risk that the inherent adhesive strength of the adhesive will not be exhibited sufficiently. Therefore, in the polishing step, which will be described in detail later, the bundled lens blocks 10' are likely to be separated.

The principle of decomposition of the phenolic antioxidant on the substrate surface is considered as follows. Ozone having strong oxidizing power is generated in the vicinity of the surface of the substrate 11 by being irradiated with ultraviolet rays of a specific wavelength. The generated ozone decomposes substances near the surface of the substrate 11 by its oxidizing power. At this time, phenolic antioxidants such as BHT are decomposed. Although the ozone that has contributed to the oxidation reaction is once decomposed, new ozone can be generated by ultraviolet rays of a specific wavelength. It is thought that the ozone generated in this manner oxidizes and decomposes substances near the surface of the substrate 11 . Therefore, it is considered that the phenolic antioxidant adhering to the surface of the substrate 11 is also decomposed.

Light to be irradiated in the purification process (hereinafter also referred to as irradiation light) may contain ultraviolet rays having a wavelength of 300 nm or less. The irradiation light preferably contains ultraviolet rays with a wavelength of 260 nm or less, more preferably at least ultraviolet rays with a wavelength of 190 nm or less.

The irradiation light may include two types of ultraviolet rays with different wavelengths. For example, the irradiation light may include ultraviolet rays of 180 nm to 190 nm and ultraviolet rays of 245 nm to 265 nm.
The energy of ultraviolet light with a wavelength of 185 nm may account for 5% or more of the irradiation energy (total spectral energy) of the irradiation light applied to the surface of the substrate 11 . In addition, such a ratio may be 50% or less.
When the energy of ultraviolet rays of 245 nm or more and 265 nm or less is taken as 100%, the relative energy of ultraviolet rays of 180 nm or more and 190 nm or less is preferably 5% or more, more preferably 25% or more. The relative energy of ultraviolet rays of 180 nm or more and 190 nm or less may be 40% or less, or may be 35% or less.

The irradiation light irradiated to the base material 11 in the purification process is applied so that the energy amount (integrated light amount) per unit area of the base material surface is 450 [mJ/cm ² ] or more and 550 [mJ/cm ² ] or less. preferably. The energy amount by one continuous irradiation may fall within the above range, or the total energy amount of multiple irradiations may fall within the above range.

In the purification step, the illuminance of the irradiation light on the surface of the substrate 11 may be 20 [mW/cm ² ] or more and 150 [mW/cm ² ] or less. Also, the distance from the irradiation light source to the substrate surface may be 5 mm or more and 80 mm or less.
In the purification step, the distance from the irradiation light source to the substrate surface is set to 10 mm or more and 40 mm or less, and the irradiation light is irradiated so that the illuminance is 50 [mW/cm ² ] or more and 100 [mW/cm ² ] or less. preferably. Thereby, the phenol-based antioxidant can be decomposed more reliably.

In the purification process, as described above, ozone gas is generated near the surface of the substrate 11 irradiated with the irradiation light. Ozone gas contributes to the decomposition of the phenolic antioxidant, so it is preferable to control the concentration of the generated ozone gas.
In the purification step, it is preferable to control the ozone gas concentration in the space where the substrate 11 is irradiated with the irradiation light to 90 ppm or more. Irradiation is performed on the substrate 11 placed in the space, and the concentration of ozone gas is reduced by newly introducing a gas that does not contain ozone gas into the space while evacuating the gas in the space. can be lowered. On the other hand, the concentration of ozone gas can be increased by reducing the amount of newly introduced gas.
More preferably, after setting the illuminance of the irradiation light and the distance from the irradiation light source to the substrate surface as described above, the ozone gas concentration is controlled to 90 ppm or more. The concentration of the above ozone gas may be controlled to 400 ppm or less.
The above ozone gas concentration may be measured at a distance of 10 mm or more and 50 mm or less from the substrate 11 .

In the cleaning step, the time for irradiating the substrate surface with the irradiation light may be 2 seconds or more and 15 seconds or less. The number of times of irradiating the substrate surface with the irradiation light may be one time or a plurality of times. The irradiation time per time may be within the above range, and the total irradiation time (total time) may be within the above range.

The cleaning step may be performed before bonding the base material surfaces of the lens block 10', which will be described in detail later, with an adhesive. In other words, the order of the lens fixing member producing step and the cleaning step is not particularly limited. In other words, the cleaning step may be performed after the lens fixing member manufacturing step is performed, or the cleaning step may be performed before the lens fixing member manufacturing step is performed. Further, the cleaning process may be performed both before and after the lens fixing member manufacturing process.
From the point of view of suppressing deterioration of the adhesive layer 13 due to irradiation of ultraviolet rays as described above, it is preferable to carry out the cleaning process before carrying out the lens fixing member manufacturing process.

In the first step, which is a step of producing a lens fixing member, a lens fixing member 15 is produced by laminating an adhesive layer 13 on one surface of a sheet-shaped base material 11 .

For example, as shown in FIG. 3A, in a state in which the base material 11 is arranged so that the thickness direction is the vertical direction, the ultraviolet rays are applied to the lower surface of the base material 11 from below, and then, as shown in FIG. An adhesive layer 13 is overlaid on the upper surface of the material 11 .

The adhesive layer 13 is made of a fixing resin composition for fixing the plurality of rod lenses 12, 12 between the two substrates 11, 11. As shown in FIG. Such a fixing resin composition may be molded into a sheet to form the adhesive layer 13 .

The fixing resin composition that forms the adhesive layer 13 preferably contains a curable resin (reactive compound) that is cured by heat treatment. Examples of reactive compounds include epoxy resins and modified products thereof, urethane resins and modified products thereof, and the like.

The fixing resin composition may further contain a silicone resin and its modified product, a polyester resin and its modified product, an acrylic resin and its modified product, a polyamide resin and its modified product, etc., in addition to the curable resin described above.

In the manufacturing method of the present embodiment, the second step includes a lens board manufacturing step of manufacturing a lens board 10″ in which a plurality of rod lenses 12 are sandwiched between adhesive layers 13 using two lens fixing members 15; and a lens block manufacturing step of manufacturing a plurality of lens blocks 10′ by dividing the lens board 10″ by cutting.

In the lens board production step of the second step, a plurality of rod-shaped rod lenses 12 are prepared. As shown in FIG. 4A, a plurality of rod lenses 12 are arranged between two lens fixing members 15, 15 manufactured as described above, and the plurality of rod lenses 12 are sandwiched between two adhesive layers 13. A lens board 10″ is produced by
In other words, the two substrates 11 are overlapped so that the adhesive layers 13 of the lens fixing members 15 sandwich the rod lenses 12 aligned in the longitudinal direction. Then, a lens board 10'' as shown in FIG. 4B is produced.
In the lens board manufacturing process, by sandwiching a plurality of rod lenses 12 while heating as described above, the fixing resin composition forming the adhesive layer 13 is given fluidity and fixed between the adjacent rod lenses 12 . The resin composition for use may be easily penetrated.

The rod lens 12 may be made of plastic or glass. The diameter of the rod lens 12 may be, for example, 0.05 mm or more and 2.00 mm or less.

In the lens board manufacturing process, the plurality of rod lenses 12 are arranged so that their longitudinal directions are aligned. In addition, a plurality of rod lenses arranged between two substrates 11 are arranged by using two lens fixing members 15 in which the adhesive layer 13 is superimposed on one surface side (the surface arranged inside) of the substrate 11. 12 are fixed by an adhesive layer 13 .
By arranging two lens fixing members 15 so that the adhesive layer 13 is arranged inside the base material 11, and sandwiching the plurality of rod lenses 12 between the two lens fixing members 15, the plurality of rod lenses 12 are formed. is surrounded by the fixing resin composition of the adhesive layer 13 . Thereby, each of the plurality of rod lenses 12 is fixed at a predetermined position between the two substrates 11 .

In the second step of manufacturing the lens block, at least one of the rod lenses 12 is cut by cutting the lens board 10'' so as to divide the rod lenses 12, 12 inside the lens board 10'' in the longitudinal direction. exposing the edge of the lens to form an exposed lens surface. In other words, the lens board 10'' is cut in the thickness direction so as to divide the rod lenses 12 in the longitudinal direction so that the rod lenses 12 form exposed lens surfaces.

In the lens block manufacturing process, for example, as shown in FIGS. 5A and 5B, the lens board 10″ is cut in the thickness direction so that the rod lenses 12 are separated in the longitudinal direction into a plurality of pieces. increases, and the lens surface is exposed at the end of the cut rod lens 12. Thus, an exposed lens surface is formed. A plurality of lens blocks 10' are produced from 10''. In the cut surface obtained by cutting the lens board 10'', the exposed lens surface and the end surface of the substrate 11 are flush with each other.

In the manufacturing method of the present embodiment, the third step is bonding by arranging and bundling a plurality of lens blocks 10' so that the substrate surfaces of adjacent lens blocks 10' face each other, and bonding the substrate surfaces with an adhesive. and a polishing step of obtaining the rod lens array 10 by polishing a plurality of exposed lens surfaces in a state in which the adjacent lens blocks 10' are bonded and bundled.

In the bonding process of the third process, first, an adhesive is applied to each base material surface of the plurality of lens blocks 10' manufactured in the lens block manufacturing process. The substrate surface to which the adhesive is applied is the surface opposite to the surface facing the rod lens 12 . In other words, the substrate surface to which the adhesive is applied is the substrate surface facing outward.
Next, a plurality of lens blocks 10' having base material surfaces coated with an adhesive are bundled. At this time, the plurality of lens blocks 10' are bundled so that the cut surfaces of the plurality of lens blocks 10' are flush with each other. In other words, the plurality of lens blocks 10' are bundled so that the exposed lens surfaces of the lens blocks 10' are aligned along the same surface. At this time, the plurality of lens blocks 10' are arranged so that the substrate surfaces coated with the adhesive are adjacent to each other and face each other.

Examples of adhesives used in the adhesion step include silicone adhesives, moisture-curable modified silicone adhesives, silyl group-containing polymer adhesives, and cyanoacrylate-containing adhesives. Commercially available products can be used as these adhesives.
The adhesive used in the adhesion step is preferably a moisture-curable adhesive that cures when moisture in the air initiates a polymerization reaction, and is preferably a cyanoacrylate-containing adhesive or a silyl group-containing polymer adhesive.
Moisture-curable adhesives are difficult to cure under conditions in which a relatively large amount of phenolic antioxidants such as dibutylhydroxytoluene are present, because the polymerization reaction is inhibited, so there is a risk that sufficient adhesive strength will not be exhibited. In the present embodiment, the phenolic antioxidant adhering to the surface of the base material to be adhered is decomposed by light irradiation in the purification step, so that the adhesive can exhibit sufficient adhesive strength. As a result, it is possible to prevent the bundle of lens blocks 10' from coming loose during the polishing step, as will be described in detail later.

In the third polishing step, the exposed lens surfaces of the bundled lens blocks 10 ′ are polished to obtain the rod lens array 10 .
The polishing process is carried out, for example, at room temperature using a polishing apparatus having a circular rotating polishing disk G, for example, as shown in FIG. 6A. The polishing disk G may have a polishing pad made of a resin containing an appropriate abrasive, and the polishing pad may be provided on the surface in contact with the lens block 10'. The polishing apparatus is configured to polish the exposed lens surface of the lens block 10' by pressing the exposed lens surface of the lens block 10' against the polishing disc G and moving it along the polishing disc G. As shown in FIG. In FIG. 6A, as an example, a workpiece (processing object) in which four lens blocks 10' are bundled and integrated is shown, but it is not limited to such an aspect. For example, it may be a workpiece in which more or less lens blocks 10' are bundled and integrated.

In the polishing step, when the bundled lens blocks 10' are subjected to the polishing process as described above, the exposed lens surfaces are pressed against the polishing disk G and the exposed lens surfaces and the surface of the polishing disk G are rubbed together, so that the adhesion is prevented. A plurality of lens blocks 10' are subjected to a force that separates them. Therefore, if the adhesive force on the base material surface bonded with the adhesive is weak, there is a risk that the substrate will come apart as shown in FIG. 6B, for example.
In the present embodiment, the phenolic antioxidant adhering to the base material surface is decomposed by the light irradiation in the purification step described above, so that the adhesive strength of the adhesive is sufficiently exerted. Therefore, since the decrease in adhesive strength on the base material surface is suppressed, it is possible to suppress the above-described separation.

After the polishing process, the bundled lens blocks 10' can be released from the bundled state by subjecting the bundled lens blocks 10' to, for example, solvent immersion treatment or mechanical peeling treatment. Thereby, it is possible to obtain a plurality of rod lens arrays 10 having exposed lens surfaces polished by the polishing process.

The rod lens array 10 manufactured as described above is used, for example, as an optical component incorporated in printers, copiers, electronic blackboards, and the like.

Next, an embodiment of a method for manufacturing a lens fixing member according to the present invention will be described.

The method of manufacturing the lens fixing member of the present embodiment is a method corresponding to the first step described above.
Specifically, the method for manufacturing the lens fixing member of this embodiment includes:
A lens fixing member is used to make a rod lens array 10 having a plurality of rod lenses 12 arranged so that their optical axes are aligned and two lens fixing members 15 that sandwich and fix the plurality of rod lenses 12 therebetween. A method for manufacturing a lens fixing member for manufacturing 15,
The lens fixing member 15 has a sheet-like base material 11 containing a resin and an adhesive layer superimposed on one surface of the base material 11,
In order to improve the adhesive strength when the surfaces of the substrates are bonded with an adhesive during the process of making the rod lens array 10, the surface of the substrate 11 is reduced by reducing the phenolic antioxidant adhering to the surface of the substrate 11. Equipped with a purification process to purify
In the purification process, the phenolic antioxidant is reduced by irradiating the surface of the substrate to which the phenolic antioxidant is adhered and which is to be adhered by the adhesive with light containing ultraviolet rays with a wavelength of 300 nm or less. to clean the surface of the base material 11 .

The method of manufacturing the rod lens array and the method of manufacturing the lens fixing member of the present embodiment are as exemplified above, but the present invention is not limited to the manufacturing methods exemplified above.
That is, various forms that can be adopted in a general method of manufacturing a rod lens array can be adopted as long as the effects of the present invention are not impaired.

Next, the present invention will be described in more detail by way of experimental examples, but the present invention is not limited to these.

A method for manufacturing a rod lens array was carried out as follows to manufacture each rod lens array of each example.

<Members and raw materials for rod lens array>
・Rod lens A rod lens with a diameter of 0.5 mm (commercially available)
・Base material Fiber reinforced plastic plate (FRP epoxy glass laminated plate commercially available)
However, since the separator containing dibutylhydroxytoluene (BHT) was used and press-molded as described above, BHT adhered to the surface.
Adhesive layer superimposed on the substrate Adhesive layer formed by the above-described curable resin (reactive compound) Adhesive Special polymer containing silyl group manufactured by ThreeBond Co., Ltd.: product name “TB1530”,
<Purification step of the first step (method for manufacturing a lens fixing member)>
The surface of the substrate to be bonded in the subsequent bonding step was irradiated with light containing ultraviolet rays. The conditions for irradiating light were varied according to each example. Specifically, irradiation was performed under the irradiation conditions shown in Table 1. However, unless otherwise specified, the following irradiation conditions were adopted.
Illuminance: 50 to 100 [mW/cm ² ]
Irradiation time: 4 to 11 seconds Ozone exposure time: 10 to 30 seconds As the light irradiation device, UV lamp "QGL400U-3B" manufactured by Iwasaki Electric Co., Ltd., illuminance meter "UVPF-A2", and light receiving head "PD-254A2" were used. A device provided as a component was used. Table 1 shows the wavelength and energy ratio of ultraviolet rays in the irradiation light. The total amount of energy (accumulated amount of light) per unit area of the substrate surface was 500±50 mJ/cm ² . Using "EG-700EIV" manufactured by Ebara Jitsugyo Co., Ltd. as an ozone concentration meter, the ozone concentration was measured for each UV irradiation condition.
Details of each condition described in Table 1 are as follows.
・Distance from the light source: Distance between the UV lamp and the substrate surface irradiated with UV ・Exhaust blower frequency: Rotational speed of the motor that drives the blower that exhausts ozone gas ・Discharge amount: Gas (air) exhausted by the exhaust blower Amount per unit time ・Ozone concentration: Ozone concentration in the space where the base material is irradiated with UV in the equipment Immediately after the irradiation of the purification process, the next lens fixing member is manufactured using the base material that has undergone the purification process. The process was performed.
<Lens fixing member manufacturing step of the first step (manufacturing method of lens fixing member)>
An adhesive layer was superimposed (laminated) on the substrate while heating to 100 to 160° C. to prepare a lens fixing member.
<Lens board manufacturing process of the second process>
Two lens-fixing members were superimposed such that a plurality of rod lenses arranged in a line with the same longitudinal direction was sandwiched between the adhesive layers of the two lens-fixing members. A lens board was thus produced.
<Second process lens block manufacturing process>
A plurality of lens blocks each having a size of 2 mm (H)×2 to 20 mm (W)×100 to 400 mm (L) were produced by cutting the lens board in the thickness direction.
<Adhesion step of the third step>
The lens blocks were adhered to each other with the above adhesive. A lens block assembly in which a plurality of (3 to 300) lens blocks are bundled was produced.
<Polishing step of the third step>
The exposed lens surfaces of the lens block assembly were polished by pressing the exposed lens surfaces against a polishing disc with a polishing pad and rotating the lens block assembly.

(Examples 1 to 22, Comparative Example 1)
Basically, rod lens arrays were manufactured by the method described above. Table 1 shows the difference in manufacturing conditions between the manufacturing methods of Examples and Comparative Examples.

<Test for confirming decomposition of dibutylhydroxytoluene (BHT) by ultraviolet irradiation (TOF-SIMS test)>
Separately, a base material (FRP) after the purification process was performed under the same conditions as in Example 2 was prepared. On the other hand, a base material (FRP) was also prepared without performing the purification process. Then, time-of-flight secondary ion mass spectrometry (TOF-SIMS) was performed on each substrate surface (FRP surface).
The analysis method conformed to the general TOF-SIMS test method. The relative intensities of C ₁₅ H ₂₃ ⁺ and C ₁₆ H ₂₃ ⁻ , secondary ions derived from BHT, were measured. The results are shown in FIG.
As can be seen from FIG. 7, it can be said that the BHT adhering to the surface of the base material was decomposed by irradiating light containing ultraviolet rays of a specific wavelength in the purification process.

<Evaluation test related to looseness of bundled lens blocks>
The number of occurrences of separation was counted when the polishing process described above was performed. Table 1 shows the evaluation results. Table 2 summarizes the effects of "ozone concentration" and "distance from the light source" on the results of the evaluation test (whether or not there is dispersion).

As can be seen from Table 1, according to the manufacturing method of the example, the exposed lens surface of the rod lens is exposed in a state in which the base surfaces of the lens blocks are bonded and bundled, compared to the manufacturing method of the comparative example. It was possible to prevent the bundled lens blocks from coming apart when being polished.
As can be seen from Table 2, in the purification process, the higher the ozone concentration and the closer the distance to the light source, the more the occurrence of scattering could be suppressed.

The rod lens array manufacturing method of the present invention is suitably used, for example, for manufacturing rod lens arrays built into optical equipment such as printers, copiers, and electronic blackboards.
The manufactured rod lens array is suitably used as a member constituting the optical equipment as described above.

10: rod lens array,
10′: lens block 10″: lens board 11: base material 12: rod lens 13: adhesive layer 15: lens fixing member
S: separator.

Claims (3)

a first step of producing a lens fixing member having a sheet-like base material containing a resin and an adhesive layer superimposed on one surface of the base material;
a second step of producing a lens board in which a plurality of rod-shaped rod lenses are sandwiched between the respective adhesive layers of the two lens fixing members, and further dividing the produced lens board to produce a plurality of lens blocks;
a third step of obtaining a rod lens array by subjecting the rod lenses of the manufactured lens block to a polishing process;
In the second step, the lens board is produced by arranging the plurality of rod lenses in the same longitudinal direction, and the lens board is cut in the thickness direction in a direction perpendicular to the longitudinal direction of the plurality of rod lenses. dividing the lens board into a plurality of lens blocks by forming an exposed lens surface on the lens blocks;
In the third step, a plurality of the lens blocks are bundled so that the exposed lens surfaces of the rod lenses are aligned, and the exposed lens surfaces are bonded to each other by bonding the base surfaces of the adjacent lens blocks with an adhesive. obtain a rod lens array by subjecting the
The first step is
a cleaning step of cleaning the surface of the substrate in order to reduce the phenolic antioxidant adhering to the surface of the substrate to be bonded and improve the adhesive strength of the adhesive;
In the purification step, the surface of the base material to which the phenolic antioxidant is adhered and to be adhered by the adhesive is irradiated with light containing ultraviolet rays having a wavelength of 300 nm or less to prevent the phenolic antioxidant. reduce drugs,
A method for manufacturing a rod lens array. 2. The method of manufacturing a rod lens array according to claim 1, wherein the base material is an epoxy glass laminate. The lens fixing member is manufactured in order to make a rod lens array having a plurality of rod lenses arranged so that their optical axes are aligned, and two lens fixing members that sandwich and fix the plurality of rod lenses. A method for manufacturing a lens fixing member comprising:
The lens fixing member has a sheet-like base material containing a resin and an adhesive layer superimposed on one surface of the base material,
In order to improve the adhesive strength when the surfaces of the base material are adhered to each other with an adhesive during the process of making the rod lens array, the amount of the phenolic antioxidant adhering to the surface of the base material is reduced. Equipped with a purification process to purify the surface,
In the purification step, the surface of the base material to which the phenolic antioxidant is adhered and to be adhered by the adhesive is irradiated with light containing ultraviolet rays having a wavelength of 300 nm or less to prevent the phenolic antioxidant. A method for manufacturing a lens-fixing member that uses less agent.

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